Refrigerator control apparatus



March 24, 1936. J. J BAUMAN 2,035,291

REFRIGERATOR CONTROL APPARATUS Filed Oct. 25, 1933 s Sheets-Shet 1 FIG.3

- INVENTOR WITNESSES:

J. J. BAUMAN 2,035,291

REFRIGERATOR CONTROL APPARATUS March 24, 1936.

Filed 001;. 25, 1933 3 Sheets-Sheet 2 INVENTOR JOHN' J. Bnumm 'FTIG.6.

WITNESSES:

ATTOR EY March 24, 1936. A v J BAUMAN A 2,035,291

REFRIGERATOR CONTROL APPARATUS Filed Oct. 25, 1933 5 Sheets-Sheet 3 ".D" ICYCLE CYCLE III E ll u a 3 U "I I 5 h Z I,

HI 4 U U 3 sess a .LIJHNZUHUJ 53:59-75 ZHD-LUZIZdWi-L BNI'IOQD I WITNESSES: 2 I INVENTOR $7 7M O JOHN J. BAUMFIN.

ATTOR Patented Mar. 24, 1936 NETE REFRIGERATOR CONTROL APPARATUS John J. Bauman, Springfield, Mass.,- assignor to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Application October 25, 1933, Serial No. 695,174

6 Claims.

My invention relates to refrigerator control apparatus for use primarily with domestic or small commercial refrigerators.

It is an object of my invention to provide a.

novel refrigerator control which-will operate re-- frigerating apparatus to obtain various temperature conditions within a refrigerator other than the heretofore usual evaporator fast liquid freezing temperatures and food compartment food preserving temperatures.

It'is another object of my invention to provide a control apparatus which, in addition to the control of the aforesaid usual operation of the refrigerating apparatus to maintain temperatures sufiiciently low to freeze ice quickly in the evaporator, preserve foodstuffs in the cabinet and incidentally accumulate frost on the evaporator, may effect operation of the refrigerating apparatus to obtain evaporator temperatures sufiiciently low to maintain frozen liquids in the evaporator in the solid state, to freeze ice slowfrost from the evaporator.

' an indicating means for determining the setting,

It' is still another object of my invention to provide a single control apparatus for obtaining at will the above conditions in a refrigerator,

by manual operation of a single readily accessible adjusting device. v

It is a further object of my invention to provide a temperature control mechanism having associated therewith a manually adjustable means for obtaining various temperatures, and

of the adjustable means.

These and other objects are efiected by my in-' vention, as will be apparent from the following description and claims taken in connection with the'accompanying drawings, forming a partof this application, in which:

Fig. 1 shows a complete refrigeration apparatus, parts thereof being broken away for the sake of clearness; I g r Fig. 2 is an enlarged'partial view of a control knob for operating my control apparatus and having an indicating means associated therewith;

Fig. 3 is a fragmentary view of one embodiment of my control apparatus;

Fig. 4 is a side view of the adjustable-eccentric device used'in my control mechanism;

Fig. 5 is a sectional view taken online V-V-5 of Fig. 6; H

Fig. 6 is a sectional view of the control mech-.- anism shown inFig.5; and m r Fig. 7 is a graph showing the various tempera! tures attained in a refrigerator operating in acm cordance, with my control on continuous operate; 1

ing cycles. Referring specifically to the drawings, numeral H designates generally a complete refrigeration apparatus including a cabinet l2 pro- 15 vided with a food compartment l3, andhaving associated therewith a refrigerating apparatus including a motor compressor unit I4 and a condenser l5 disposed in a machinery compartment l6 of the cabinet l2. An evaporator or cooling 20 unit l1, preferably formed of sheet metal to provide a partially enclosed freezing compartment l8 for freezing liquids or desserts, is disposed in the food compartment I3. The evaporator, condenser and compressor are connected together 25 by suitable refrigerant conduits and valves, as is well understood in theart. A control mechanism l9 supported on a single stationary supporting mechanism 20, is disposed in .the machinery compartment 16.. A shaft 2| having a 30 knob 22 for adjusting the control mechanism I9, and. provided with a pointer 23 on the outer end thereof, extends through a panel 24 of the machinery compartment l6, which panel has a lettered dial 25 associated with the pointer 23. 35 A, bulb 26, filled with an expansible gas, is mounted on or adjacent to the cooling unit Ill, and a conduit 21 extends from the bulb 26 to the control mechanism to operate the same in response to cooling unit temperatures, as 40 hereinafter described. Referring now to Figs. 5 and 6 for'a detailed description of one embodiment of my control mechanism, numeral 28 designates a sylphon bellows connected to the pipe 21 and, therefore, it 45 expands and contracts with the gas in the bulb-*- 26 in response to temperature changes at the evaporator Il. A spring 29 opposes the force' of the bellows. Movement of the bellows due to slight changes in pressure of the gas'therein in 50 response to changes in evaporator temperature, is transmitted to a switch operating lever 30, which in turn operates a snap switch 3| to open and close contacts 32.

A pair of eccentrics 33 bear on a pin 34 slidably mounted in a slot 35 formed in a rigid member 36 supported from the base through a supporting member 37. The pin 34 is connected to the switch operating lever 30. The eccentric 33 is fixedly mounted on the shaft 2| which shaft is rotatably mounted on a'cradle 38 and, as hereinbefore stated, extends through the panel 24 and has a knob 22mounted thereon.

As the 'knobis turned in a counterclockwise directiomthe shaft 2| and, eccentric 33 are also rotated counterclockwise, and, because of the shape of the eccentric, the pin 34 is lowered-in the slot 35 thus lowering the right end of the switch operating lever 30. As. the right end of the lever is lowered, the lever is rotated about the bellows 28 as a'pivotby the force of the spring 29 and left end-of the lever 30 is raised. It is therefore necessary-for the bellows 28 to expand a. less distance in order to cause closure of the contacts 32. The motor compressor imit ll will therefore operate to obtain a lower temperature in the evaporator.

If the control is set on the #2 position, the unit 14 cycles between the evaporator temperatures, for example,- of 4 F., at which temperature the switch opens, and 20 F., at which temperature the switch closes, the mean evaporator tempera 'ture therefore, being 12F.

When the eccentric 33 is rotated to the furthermost counterclockwise position, as determined by a stop 39 on the eccentric engaging withthe pin 3, the bellows 28 is unable to contact sufliciently to drop the switch lever 30 to the point where the snap switch 3| operates to open the contacts 32. The motor-compressor unit It will, therefore, operate continuously regardless of cooling unit temperature.

Similarly, if the knob 22, shaft 2| and-eccentric 33 are turned in a clockwise direction, the bellows 28 must expand a greater distance to close the contacts 32, the motor-compressorunit 14,, therefore, operating less, whereby a higher temperature is obtained in the evaporator IT.

If'the control is set on the #5-position, the unit I! cycles betweien the evaporatortemperatures of, for example, 6 F., at which temperature the switch opens, and 30 F., at which temperature the switch closes, the mean evaporator tempera-, ture, therefore, being23" F. l

When the eccentric 33 is rotated to the furthermost clockwise position, designated at l in Fig. 2, as determined by the stop 39 on the eccentric engagingwith thepin 34, a projection 40 on the eccentric 33- engages a lever 4i,.pivoted at 42 to raise the left end of the lever 4| The end of the lever 4| engag the switch operating lever 30 to prevent it from dropping a suflicient distance to operate snap switch 3| to close the contacts 32. Regardless of evaporator temperature, therefore, the motor-compressor unit will remain inactive, and the food compartment temperature may approximate room temperature. justable mechanism provides a range of temperatime therefore from continuous'running to -continuous off. Positions I to 5 on theidial 25, corresponding to respective depressions 33a in the eccentric 33 in the space from A to B, operate the motor-compressor unit 14 to freeze liquids placed in the freezing chamber l8 and to preserve foodstuffs at mean evaporator temperatures of,

for example, from 12 F. to 23 F. Frost is in-.

eldentally accumulated on the evaporator because the evaporator temperature is below the dew point temperature of the air within the box,

This ad-.

moisture therefore condensing and freezing on the evaporator.

The two positions of adjustment prior to the ofi position of the control mechanism are marked E" and D on the dial 25.and correspond to the depressions of the eccentric shown at B to C and C to F respectively (Fig. 4). At the E position, the lever is in such a position that the evaporator temperatures at which the motor-com-' pressor unit l4 turns off and on are sufficiently low to maintain liquids in the solid state in the from rapid air circulation induced by the cold evaporator l1. However, the temperatures obtained over large areas of the evaporator, by cycling of the motor-compressor unit at the reduced rate obtained by placing the control knob 22 at E, are not sufliciently low to add frost thereto, since the temperatures of large surfaces of the evaporator are above the freezing point of the moisture in the air within the food compartment l3.

' It has been found that an on temperature of F. and an off position of 22 F., giving a mean temperature of 28.5 F., is capable of attaining the desired results. This is partly due to the fact that the refrigerating mechanism runs about one-third of the time. .Therefore, about twice the time is required to start the mechanism after the low temperature limit has been reached as tostop it when the high temperature is reached. The average temperature of the cooling temperatures-are, however, given by way of example, and are-not consideredas limitations.

' unit is, therefore, somewhat above 28.5 F. These The E adjustment, therefore, provides for extremely economic and satisfactory operation of a mechanical refrigerator. Liquids are maintained in a solid state in the freezing space and may be frozen therein over a period of time. Food is preserved in the food storage chamber and frost is not added to the evaporator, whereas foods are not dehydrated, since some of the moisture which condenses on the evaporator is again picked up by the air in the refrigerator cabinet. The air is therefore maintained at a fairly high relative humidity of, for example, 60 to 70%, thus approaching ideal refrigeration con'ditiona. At ,the same time, the refrigerator apparatus is cycling at a comparatively low rate, whereby energy is saved. The refrigerating apparatus may be operated with a control set at the E position at all times except when an extremely low temperature is desired in the food storage compartment or when liquids are to be frozen quickly. All the desirable functions of automatic refrigeration are hydration of food and-subsequent excessive fros ing of the cooling unit in the refrigerator.

When the controlmechanism is set at the D position, the motor-compressor unit l4 continues,

to cycle but at a slower rate than when operating in the E position. The temperatures of the food compartment l3 and the evaporator I! are sufficiently high to melt frost from the evaporator if any has accumulated thereon, while cycling of the motor-compressor unit I4 maintains temperatures in the food compartment l3 sufliciently low 'to preserve the average foodstuffs. The evaporator I! is, therefore, defrosted, and, at the same time, food preservation is assured in the case where the user neglects to turn the control knob 22 to end the defrosting period. The successive off and on temperatures obtained at the evaporator when the control is set at the D position, range, are for example,. from 30 F. to 42 F., as shown in the graph, Fig. '7, themean evaporator temperature, therefore, being 36 F.

The single control knob 25, manually movable, is capable of providing all the adjustments including continuous running operation at l, fast freezing operation from 2 to 5, economy operation at E, defrosting operation at D and completely inactive at off.

Referring now to Fig. 3 for a description of the second embodiment of my invention, a portion of a control mechanism is shown which is similar to the control mechanism of Figs. 6 and '7 ex-v cept that springs 43 and 4 4 are provided in the rigid member 35 of the control mechanism, the spring 45 being disposed at.a lower horizontal level than the spring 43. The spring 44 is so disposed that, when the control knob 25 is set at the E position, and the eccentric moves correspondingly, the left end of the switch operating lever 33 is raised sufficiently that it must overcome the force of the spring 44 before the snap switch 3| closes the contacts 32. The bellows 28 must, therefore, overcome a bias in addition to the bias of the main spring 29 thus pro viding for switch closing at higher evaporator temperatures. These temperatures correspond to the economy conditions obtained when the control is set at the E position in the first embodiment of my invention'b The other spring 43 is so disposed .that, when the control knob 25 is set at the D position and the eccentric moves correspondingly, the left end of the switch lever 33 is raised sufiiciently that it must overcome the additional bias of both spring 64 and spring 63, before the snap switch 3!! closes the contacts 32, thereby obtaining higher temperatures at the evaporator H than obtained either at positions 1 to 5 or E, which temperatures are sufficiently high to defrost the evaporator and sufliciently low to preserve foodstuffs, and correspond to temperatures obtained when the control in the first embodiment of my invention is set at the D position.

The position of the cam 33 when set in the E or D positions in itself provides for high cycling temperatures and highrelative humidities, springs 53 and 43 determining the uppertemperatures at which cycling will occur.

While I show a single control knob, a single supporting mechanism and a single switch for effecting all the functions of my control apparatus, it is to be understood that my invention is not confined or limited to embodying all of these functions in a single knob, switch or supporting mechanism.

From the foregoing, it will be apparent that I have provided a novel control mechanism for chtaining (1) operation of the refrigerating apparatusto effect quick freezing of liquids, (2) economic operation of the apparatus to maintain a high relative humidity, to preserve liquids in a frozen state and to retard the addition of frost, and (3) operation of the refrigerating apparatus to defrost the apparatus; all three conditions beplaced thereupon as are imposed by the, prior art or as are specifically set forth in the appended aclaims. I

What I claim is:

1. In a control mechanism for a refrigerator having a food storage compartment and an evaporator disposed in heat exchange relation therewith and having a space for freezing liquids, the combination of means for operating the ref rigerator to obtain various mean evaporator temperaturessufiiciently low to freeze liquids in said space, preserve foodstuffs in the food storage compartment, and incidentally accumulate frost on the evaporator, means for operating the refrigerator ciently low to maintain frozen liquids in said space in the solid stage, to preserve foodstuffs in the food storage compartment, to substantiallyto obtain a mean evaporator temperature sufliprevent the addition of frost on the evaporator,

and to maintain a high relative humidity in the food storage compartment, and means for operating the refrigerator to obtain a mean evaporator temperature sufficiently low to preserve foodstuffs in the food storage compartment and sufiiciently. high to melt frost off the evaporator.

2. In a control mechanism for a refrigerator having a food storage compartment and an evaporator disposed in heat exchange relation therewith and having a space for freezing liquids, the combination of means for operating the refrigerator to obtain mean evaporator temperatures sumciently low to freeze liquids in said space; preserve foodstuffs in the food storage compartment,

and incidentally accumulate frost on the evaporator, and means for operating the refrigerator to obtain a mean evaporator temperature sufficiently low to maintain frozen liquids in said space in the solid state, to preserve foodstuffs in the food storage compartment, to substantially prevent the addition of frost on the evaporator,

and to maintain a high relative humidity in the food storage compartment.

3. A method of operating a refrigerator for preserving foodstuifs, which refrigerator includes a cabinet and a cooling element disposed therein having a space for freezing liquids, which method comprises cycling the machine to maintain a mean temperature in the cooling element which is sufiiciently low to preserve foodstuffs, freeze liquids in' said spaceand incidentally cause frost to accumulate on the cooling element, and selectively cycling the machine to maintain a relatively higher mean temperature in the cooling element, which higher mean temperature is sufiiciently low to maintain liquids frozen in said space in substantially the solid state and to preserve foodstuffs in the cabinet, and which higher mean temperature is sufficiently high to substantially prevent the addition of frost to the cooling element and to maintain a high relative humidity in the cabinet.

4. A control mechanism fora refrigerator, which refrigerator includes a food storage compartment and a cyclically-operated refrigerating unit embodying a cooling element disposed in the food storage compartment for abstracting heat therefrom and having a space for freezing liquids, the combination of manually operable uids in said space in the solid state, preserve foodstuffs in the food storage compartment, to substantially prevent the addition of frost to the cooling element, and to maintain a high relative humidity in the food storage compartment.

5. In a control mechanism for a refrigerator,

=which refrigerator includes a food storage compartment'and a cyclically-operated refrigerating unit embodying a cooling element disposed in the food storage compartment for abstracting heat therefrom and having a spac'efor freezing liquids, the combination of manually-operable.

means readily adjustable to a plurality of positions, and temperature responsive means for starting and stopping the refrigerating unit responsive to one adjustment of-said adjustable means for maintaining the' cooling element at a mean temperature sufficiently low to freeze liquids in said space, preserve foodstuffs in the food storage compartment and incidentally accumulate frost-on the cooling element, and responsive to a second adjustment of the adjustable means for maintaining a relatively higher mean cooling element temperature sufliciently low to preserve frozen liquids in said space in the solid state, to preserve foodstuffs in the food storage compartment, to-substantially prevent the addition of frost to the cooling element, and to maintain a high relative humidity in the food storage compartment, and further responsive to a third adjustment of the adjustable means for maintaining a relatively still higher mean cooling element temperature sufficiently low to preserve foodstuffs in the food storage compartment and sufflcientlyhigh to melt frost off the cooling I element.

6. In control mechanism for a refrigerator, which refrigerator includes a food storage compartment and a cyclically-operated refrigerating unit embodying acoo1ing element disposed in the food storage compartment for abstracting heat therefrom and for freezing liquids, the combination of a switch for cycling the refrigerating mechanism, temperature-responsive means for actuating the switch, indicating means embodying a normal operating designation, a defrosting designation and an intermediate distinctive operating designation, and means cooperating with said temperature-responsive means and selectively positionable to said normal operating designation to maintain a mean temperature in the "cooling element which is sufliciently low to preserve foods in the food storage compartment and to produce ice in the cooling element and incidentally accumulate frost on the cooling element and also selectively positionable to said distincttive operating designation to'maintain a relatively higher temperature in the food storage compartment, which higher temperature is sufficiently low to preserve foodstuffs and sufiiciently high to retard the accumulation of frost on the coolingelement and maintain a relatively high humidity in the food storage compartment.

JOHN J. BAUMAN. 

